Cleanup: Put more plugin code behind the ENABLE_PLUGINS ifdef.

content/common/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//content/common/common.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
 source_set("common") {
@@ skipping 158 matching lines @@
       "gpu/gpu_memory_buffer_factory_x11.cc",
     ]
   }
 
   if (enable_plugins) {
     deps += [
       "//ppapi:ppapi_shared",
     ]
   } else {
     sources -= [
+      "pepper_file_util.cc",
+      "pepper_file_util.h",
+      "pepper_messages.h",
       "pepper_plugin_list.cc",
       "pepper_plugin_list.h",
+      "pepper_renderer_instance_data.cc",
+      "pepper_renderer_instance_data.h",
+      "plugin_list.cc",
+      "plugin_list.h",
+      "plugin_list_posix.cc",
       "sandbox_util.cc",
     ]
   }
 
   if (is_android) {
     sources += [
       "gpu/media/android_video_decode_accelerator.cc",
       "gpu/media/android_video_decode_accelerator.h",
     ]
 
@@ skipping 82 matching lines @@
 
 mojom("mojo_bindings") {
   sources = [
     "render_frame_setup.mojom",
   ]
 
   deps = [
     "//mojo/public/interfaces/application:application",
   ]
 }